Remove support for Javascript warnings in the VM.

runtime/vm/intermediate_language_arm64.cc

Index: runtime/vm/intermediate_language_arm64.cc
diff --git a/runtime/vm/intermediate_language_arm64.cc b/runtime/vm/intermediate_language_arm64.cc
index e8bd7597d3008cd8dd183741aa604c70c5e6284f..0029aaf6d2f2914f4bb4dbecf3106d7508fa4b9c 100644
--- a/runtime/vm/intermediate_language_arm64.cc
+++ b/runtime/vm/intermediate_language_arm64.cc
@@ -2667,20 +2667,6 @@ void CheckStackOverflowInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
 }
 
 
-static void EmitJavascriptOverflowCheck(FlowGraphCompiler* compiler,
-                                        Range* range,
-                                        Label* overflow,
-                                        Register result) {
-  if (!RangeUtils::IsWithin(range, -0x20000000000000LL, 0x20000000000000LL)) {
-    ASSERT(overflow != NULL);
-    __ LoadImmediate(TMP, 0x20000000000000LL);
-    __ add(TMP2, result, Operand(TMP));
-    __ cmp(TMP2, Operand(TMP, LSL, 1));
-    __ b(overflow, HI);
-  }
-}
-
-
 static void EmitSmiShiftLeft(FlowGraphCompiler* compiler,
                              BinarySmiOpInstr* shift_left) {
   const LocationSummary& locs = *shift_left->locs();
@@ -2704,9 +2690,6 @@ static void EmitSmiShiftLeft(FlowGraphCompiler* compiler,
     }
     // Shift for result now we know there is no overflow.
     __ LslImmediate(result, left, value);
-    if (FLAG_throw_on_javascript_int_overflow) {
-      EmitJavascriptOverflowCheck(compiler, shift_left->range(), deopt, result);
-    }
     return;
   }
 
@@ -2736,9 +2719,6 @@ static void EmitSmiShiftLeft(FlowGraphCompiler* compiler,
       __ SmiUntag(TMP, right);
       __ lslv(result, left, TMP);
     }
-    if (FLAG_throw_on_javascript_int_overflow) {
-      EmitJavascriptOverflowCheck(compiler, shift_left->range(), deopt, result);
-    }
     return;
   }
 
@@ -2783,9 +2763,6 @@ static void EmitSmiShiftLeft(FlowGraphCompiler* compiler,
     // Shift for result now we know there is no overflow.
     __ lslv(result, left, TMP);
   }
-  if (FLAG_throw_on_javascript_int_overflow) {
-    EmitJavascriptOverflowCheck(compiler, shift_left->range(), deopt, result);
-  }
 }
 
 
@@ -2921,9 +2898,6 @@ void BinarySmiOpInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
         UNREACHABLE();
         break;
     }
-    if (FLAG_throw_on_javascript_int_overflow) {
-      EmitJavascriptOverflowCheck(compiler, range(), deopt, result);
-    }
     return;
   }
 
@@ -3066,9 +3040,6 @@ void BinarySmiOpInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
       UNREACHABLE();
       break;
   }
-  if (FLAG_throw_on_javascript_int_overflow) {
-    EmitJavascriptOverflowCheck(compiler, range(), deopt, result);
-  }
 }
 
 
@@ -4527,9 +4498,6 @@ void UnarySmiOpInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
       Label* deopt = compiler->AddDeoptStub(deopt_id(), ICData::kDeoptUnaryOp);
       __ subs(result, ZR, Operand(value));
       __ b(deopt, VS);
-      if (FLAG_throw_on_javascript_int_overflow) {
-        EmitJavascriptOverflowCheck(compiler, range(), deopt, value);
-      }
       break;
     }
     case Token::kBIT_NOT:
@@ -4645,9 +4613,6 @@ void DoubleToIntegerInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
   __ CompareImmediate(result, 0xC000000000000000);
   __ b(&do_call, MI);
   __ SmiTag(result);
-  if (FLAG_throw_on_javascript_int_overflow) {
-    EmitJavascriptOverflowCheck(compiler, range(), &do_call, result);
-  }
   __ b(&done);
   __ Bind(&do_call);
   __ Push(value_obj);
@@ -4695,9 +4660,6 @@ void DoubleToSmiInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
   __ CompareImmediate(result, 0xC000000000000000);
   __ b(deopt, MI);
   __ SmiTag(result);
-  if (FLAG_throw_on_javascript_int_overflow) {
-    EmitJavascriptOverflowCheck(compiler, range(), deopt, result);
-  }
 }
 
 
@@ -5011,9 +4973,6 @@ void MergedMathInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
     __ add(TMP, result_mod, Operand(right));
     __ csel(result_mod, TMP, TMP2, GE);
     __ Bind(&done);
-    // FLAG_throw_on_javascript_int_overflow: not needed.
-    // Note that the result of an integer division/modulo of two
-    // in-range arguments, cannot create out-of-range result.
     return;
   }
   if (kind() == MergedMathInstr::kSinCos) {